Determination of fetal occiput position by ultrasound during the second stage of labor

OBJECTIVE: To investigate whether ultrasonography is superior to vaginal examination for determination of fetal occiput position during the second stage of labor. METHODS: We conducted a prospective cohort study of 44 parturients. During the second stage of labor, an attending obstetrician performed a vaginal examination to detect fetal occiput position. This was followed by combined abdominal and perineal ultrasound examination. The two methods were compared to the true position. Results were analyzed using Student's t test for quantitative parameters. McNemar's and Fisher's exact tests were applied in order to examine differences between the study groups. RESULTS: The error rate in detecting fetal occiput position was significantly lower using the ultrasound technique (6.8%) compared to vaginal examination (29.6%, p = 0.011). Parity, maternal body mass index or fetal weight had no influence on the error rate. CONCLUSIONS: Ultrasonographic determination of the fetal position is an accurate technique and is superior to vaginal examination.